Power - What route to go now??

New poster! (less than 10 posts)

Hi guys, looking to order up the parts for my new engine build, but wanted to rack the brains of the guru's before I do.

Here's my current set up:

KTR - Level 3 gas flowed head.
Uprated head gasket set and bolts.
KTR uprated cam.
Group N Clutch.
Lightened Flywheel.
KTR alloy intercooler, group A carb, group A dump valve, induction kit, in-car boost kit.
Hi output starter motor.
Samco hoses
Garrett T2 Turbo
Scorpion Exhaust

The car was running 20psi all the time and never gave me any issues. The main reason for the rebuild is to refresh the bottom-end.... and here's my question........

Would it be ok to fit forged pistons, but not the forged con-rods and steel liners to run 25+ psi?? I know this sounds a bit 'bodge', but there's a massive price difference and TBH, I only want to run a bit more power than what it was before.

Any help would be appreciated.

from what ive read many times over

standard piston and liners
standard carb (not a group A)
decent intecooler
T25 or T28 turbo
an Lm-1 afr gauge of some sort
and someone who can help you drill your carb jets to suit 20psi.

should make all the difference if your already running a decent Cam.

my word isnt gospel just what ive read a few times

New poster! (less than 10 posts)

I think I remember reading that the standard pistons and rings won't cope with going over 20psi. :confused:

Quote:

---

from what ive read many times over

standard piston and liners
standard carb (not a group A)
decent intecooler
T25 or T28 turbo
an Lm-1 afr gauge of some sort
and someone who can help you drill your carb jets to suit 20psi.

should make all the difference if your already running a decent Cam.

my word isnt gospel just what ive read a few times

---

:agree::agree::agree::agree::agree:

Firstly a T2 is a tiny turbo IMO and would be dead at 25psi... thats up to you and what you want the car for.. Also stock cast pistons are fine to high levels of boost (even 500Wheel!!!!hp+ in other cars) depending on tapper and piston to wall clearances (machine your own maybe)... I havnt messured stock GT pistons over a forge so i cant say there..

Quote:

---

Originally Posted by Big Supes

New poster! (less than 10 posts)

I think I remember reading that the standard pistons and rings won't cope with going over 20psi. :confused:

---

not sure, but i do believe some of the quicker cars on the 1/4mile may have run on standard pistons/liners. up to 23psi i think.

id be more worried about fueling for 25 psi in 4th and 5th than your pistons at present.

:cool:

New poster! (less than 10 posts)

Quote:

---

Originally Posted by Rob@Backyardracing

Firstly a T2 is a tiny turbo IMO and would be dead at 25psi... thats up to you and what you want the car for.. Also stock cast pistons are fine to high levels of boost (even 500Wheel!!!!hp+ in other cars) depending on tapper and piston to wall clearances (machine your own maybe)... I havnt messured stock GT pistons over a forge so i cant say there..

---

Yeah, there's other ancillaries I'd replace to go over 20 psi... I was just referring to the internals.

That's f'in awesome news regarding the standard pistons! :) With the money I could save, I wonder if a machine shop could sort the piston to wall clearances.....

I know the forge pistons lower the compression.

Quote:

---

Originally Posted by Maka

not sure, but i do believe some of the quicker cars on the 1/4mile may have run on standard pistons/liners. up to 23psi i think.

id be more worried about fueling for 25 psi in 4th and 5th than your pistons at present.

:cool:

---

Yeah, fueling and cooling (boost) are my two main concerns. Thinking about trading in my uprated cam for K-tecs 285 cam and uprated valve springs.

Does anyone know if the standard fuel pump is up to the job of big boost??

I think you should use your old pistons with new liners and rings, if your planning a rebuild its what i do. Maybe machine the crown off only depending on what your head hight messures at (if its been skimmed alot before) and what your plan is for the engine... Piper 285 and T28 seems a proven winner for good power. Spend your cash on set ups and good charge cooling..:agree: The Ph1 GT fuel pump will work ok, check to see what you have fitted allready??? black rubber casing over pump then bin it... it wont be uprated

Cool.... sounds like a good plan. :)

When replacing the liners, would you recommend going for the steel liners that K-tec supply or just go for standard replacements?

K-tec's T28's are insanely expensive. Do you know of any other reputable tubbys that people use?

Poss Adam L on here for a turbo is best bet :confused: i get alot of my parts from US these days or ATP so cant say... Standard liners will do fine... All in set up and balance of parts...

Sh!t.... and there was me grumbling that I had to pay £25 to join this club, but in hindsight it has saved me over a grand already! Cheers! :)

Will possibly get in touch with Adam regarding the turbo. Think it could be wise to get the crank lightened/balanced/knife edged while it's all out.

Lol Nope no real point in that either... GTs are cheap as chips to tune and rebuild and the ££££ - BHP its cheap.... If your after a rebuild just do a stock rebuild with new rings and shells, gaskets etc full check over... Poss cam swap + springs and turbo then spend time and cash on getting it set up.. THIS IS the main reason why so many fail. Peeps dont have them set up correctly etc..:)

Sweet! I'm going to sleep tonight with a big grin on my face. :D

Totally agree about peeps not getting them setup right. I always took mine to K-tec to get it done and it never gave me any issues at all, despite people constantly telling me it would go pop "because it a GTT". :rolleyes:

Quote:

---

Originally Posted by Big Supes

Sweet! I'm going to sleep tonight with a big grin on my face. :D

Totally agree about peeps not getting them setup right. I always took mine to K-tec to get it done and it never gave me any issues at all, despite people constantly telling me it would go pop "because it a GTT". :rolleyes:

---

Honestly mate tune the carb yourself or have some help from here, the carbs from 'tuners' have been known to never fuel correctly, you'll gain abit more just from that itself.

I may get the whole thing tuned on a RR and have a look it then. Will definitely consult you guys before hand though. :agree:

Make sure you go to a decent RR, there maybe some members on here who can recommend a place to go...

The club is full of people who have been tuning there cars for years and do a better job than the tuners... :)

Sweet. Once it's up and running I'll maybe looking into meeting up or something with some of the guru's on here to get it dialed in. Either that or just take some advice while trying to do it myself.

Ah sweet as another member on the south coast, if you need a hand with anything give us a shout.

Awesome, mate. Cheers.

May take you up that. :D

I'll stand by and drink the beer.

I like your style. :D

what i found form experience is big tuner names drop big main jets in and alter the air corrector.

bout as far as they go. therefore over fueling during normal driving and under fueling on full boost.

ditch the group A carb and read this article steve did: https://www.rtoc.org/boards/showthread.php?t=460


works a treat :cooter:

mine has dished std pistons, std liners and std rods, runs up to 27psi manifold... got a MSM high comp engine but std parts

Quote:

---

Originally Posted by Maka

what i found form experience is big tuner names drop big main jets in and alter the air corrector.

bout as far as they go. therefore over fueling during normal driving and under fueling on full boost.

ditch the group A carb and read this article steve did: https://www.rtoc.org/boards/showthread.php?t=460


works a treat :cooter:

---

Just subscribed to that thread for future reference. :agree: My car definitely felt as if it was over fueling during normal driving.

Quote:

---

Originally Posted by markey b

mine has dished std pistons, std liners and std rods, runs up to 27psi manifold...

---

Nice.... what turbo are you running? Any idea how many horses you're putting out?

:)

Quote:

---

got a MSM high comp engine but std parts

---

what does that involve?

Cheers

o.e piston ringlands won't like prolonged use over 1.5bar (*), so if you're planning on running more than that, go forged (J.E is my recommendation).

o.e liners will take a fair bit more boost than that, but again there are forged (and graphite) liners available if needs be. In my experience though, they're not needed.

The bottom-end is pretty much bullet-proof, so the o.e rods will be fine for whatever you chuck at them, and likewise for the crank & its bearings/shells as well.

* And if that is the case, you'll need to look at improving fuel supply (float chamber) too.

Quote:

---

Originally Posted by Big Supes

Nice.... what turbo are you running? Any idea how many horses you're putting out?

---

runs a VNT, dyno figures are 217bhp 256.4lb/ft torque but dyno figures are just that, and i'm sure need to be taken with pinch of salt. did a 105terminal at pod on road tyres so is probably around that figure somewhere.

as for the high comp engine, i think markeymark knows a bit about them, but last i heard there is easier ways of tuning the c1j

Quote:

---

Originally Posted by Mart

o.e piston ringlands won't like prolonged use over 1.5bar (*), so if you're planning on running more than that, go forged (J.E is my recommendation).

o.e liners will take a fair bit more boost than that, but again there are forged (and graphite) liners available if needs be. In my experience though, they're not needed.

The bottom-end is pretty much bullet-proof, so the o.e rods will be fine for whatever you chuck at them, and likewise for the crank & its bearings/shells as well.

* And if that is the case, you'll need to look at improving fuel supply (float chamber) too.

---

Ideally, I'd like to go 30psi.... would you recommend maybe just go for the forge pistons then? I was under the impression that the standard ones would be fine if I had the crowns machined down. :)

Compression ratio wise, it'll help at 30psi, but the ringlands won't be upto the job. Give it a trackday or several runs at the Pod, and they'll crack quicker than humpty dumpty falling off a wall.

30psi will take some trick fuelling/carb jetting.

Aim for a power figure rather than a max boost figure...

Quote:

---

Originally Posted by markey b

runs a VNT, dyno figures are 217bhp 256.4lb/ft torque but dyno figures are just that, and i'm sure need to be taken with pinch of salt. did a 105terminal at pod on road tyres so is probably around that figure somewhere.

as for the high comp engine, i think markeymark knows a bit about them, but last i heard there is easier ways of tuning the c1j

---

Yeah, dyno's can be a bit hit and miss, but even so, that's quite a good torque reading.

Quote:

---

Originally Posted by Mart

Compression ratio wise, it'll help at 30psi, but the ringlands won't be upto the job. Give it a trackday or several runs at the Pod, and they'll crack quicker than humpty dumpty falling off a wall.

---

Noted. :agree::agree:

Forgies will have to be ordered in that case.

Quote:

---

30psi will take some trick fuelling/carb jetting.

Aim for a power figure rather than a max boost figure...

---

It's a bit of a bugger as I never got a power reading as the car is now @ 20psi. All I know is that not a lot of cars could keep up with it off the lights. When I say I'd like 30 psi, I'm just estimating a 30% power increase.

And old c1j rule of thumb, in most cases anyway - For every psi of boost you increase, you'll gain ~5hp.

Quote:

---

Originally Posted by Big Supes

Noted. :agree::agree:

Forgies will have to be ordered in that case.



It's a bit of a bugger as I never got a power reading as the car is now @ 20psi. All I know is that not a lot of cars could keep up with it off the lights. When I say I'd like 30 psi, I'm just estimating a 30% power increase.

---

will the geabox take a prolonged use of 30psi? even if you crack the fueling for the carb!!

Quote:

---

Originally Posted by Mart

And old c1j rule of thumb, in most cases anyway - For every psi of boost you increase, you'll gain ~5hp.

---

Ahh, quite a handy one to know (as a gauge).

Quote:

---

Originally Posted by Maka

will the geabox take a prolonged use of 30psi? even if you crack the fueling for the carb!!

---

Not sure, tbh.

Someone once told me that the gearbox off the diesal 1.7 (I think) R5 is a good option. Apparently it gives a higher top end and is more durable...

Quote:

---

Originally Posted by Big Supes

Ahh, quite a handy one to know (as a gauge).



Not sure, tbh.

Someone once told me that the gearbox off the diesal 1.7 (I think) R5 is a good option. Apparently it gives a higher top end and is more durable...

---

over 80mph my doors try to open themselves and i swear i can hear the front wings creaking! :p

not sure personally with my car id want to be aiming for a high topend

Quote:

---

Originally Posted by Maka

over 80mph my doors try to open themselves and i swear i can hear the front wings creaking! :p

not sure personally with my car id want to be aiming for a high topend

---

I think there is something wrong with your car mate if it does all of that at 80!!:eek: 140mph and i would agree with you.

Quote:

---

Originally Posted by Maka

over 80mph my doors try to open themselves and i swear i can hear the front wings creaking! :p

not sure personally with my car id want to be aiming for a high topend

---

Yeah, I agree with Matt that something is up with your car. :D

It's not so much that I want to go faster.... having a high gear ratio would bring the revs down while motorway cruising.

Quote:

---

Originally Posted by Big Supes

Yeah, I agree with Matt that something is up with your car. :D

It's not so much that I want to go faster.... having a high gear ratio would bring the revs down while motorway cruising.

---

:laugh:..sounds like a lie...;), standard boost rules...:cooter:, you can keep your monthly rebuilds and eternal quests for reliability...:wasntme:...:laugh:, seriously though, 25-30psi..id reccomend you give these guys a call ... http://www.theaa.com/search-index.js...oogleBrand...:)

Quote:

---

Originally Posted by MATT C Ringworm Tuning

I think there is something wrong with your car mate if it does all of that at 80!!:eek: 140mph and i would agree with you.

---

you can definatly see day light through the top of the door when accellerating at full pelt over 80mph
and no not through the window.

my cars beautiful, nothing wrong with that! :D

also worth noting, 20psi on a t2 is no comparison to 20psi on a t28.

a bigger turbo (t28 or so) at the same boost as your running now will yield
far more power, so again, dont aim for a max boost figure, aim for a target hp.

i`d suggest going out in a gtt with a t28 fitted before you spend any money
and decide if you like the power/delivery. ;)

as for forged vs cast pistons, maybe just luck, but i had a set of wossner forged pistons in my gtt, and they took far less abuse to detroy than old stock cast jobbies,
in fact they lasted a full week, and was £500 :(

Quote:

---

Originally Posted by Maka

you can definatly see day light through the top of the door when accellerating at full pelt over 80mph
and no not through the window.

my cars beautiful, nothing wrong with that! :D

---

If you have flappy doors get the doorpins done;)

Quote:

---

Originally Posted by jesus in the seat of a 5

:laugh:..sounds like a lie...;), standard boost rules...:cooter:, you can keep your monthly rebuilds and eternal quests for reliability...:wasntme:...:laugh:, seriously though, 25-30psi..id reccomend you give these guys a call ... http://www.theaa.com/search-index.js...oogleBrand...:)

---

PMSL :D

Jesus, you speak wise words, but taking the sensible option has never been a strong point of mine. :wasntme: If it was, I'd keep my Nissan Micra and sell the 5. :eek:

My GTT has run 20 psi for around 2 and half years with no serious problems. I think the only thing that kept letting go was clutch cables..... still need to do the soft pedal mod. :cool:

There's no doubt that I won't go for big power if it means it could break any second. :)

Quote:

---

Originally Posted by Rob@Backyardracing

also worth noting, 20psi on a t2 is no comparison to 20psi on a t28.

a bigger turbo (t28 or so) at the same boost as your running now will yield
far more power, so again, dont aim for a max boost figure, aim for a target hp.

i`d suggest going out in a gtt with a t28 fitted before you spend any money
and decide if you like the power/delivery. ;)

---

Good point. :agree:

Taking on board your point, I think I'll still be going T28; even though the GTT is great fun @ 20 psi with a T2, I'd still like more power. If it turns out that 20 psi delivered from a T28 will do the job, it'll be a bonus as the engine will be capable of more (won't be pushed to the limit).

Quote:

---

as for forged vs cast pistons, maybe just luck, but i had a set of wossner forged pistons in my gtt, and they took far less abuse to detroy than old stock cast jobbies,
in fact they lasted a full week, and was £500 :(

---

Sh!t!! :eek: Sounds like bad luck to me. :(

Quote:

---

Originally Posted by Brigsy

If you have flappy doors get the doorpins done;)

---

its on the list of things to do.

thanks fella

Just bought a ported and polished inlet manifold.... they seller claims it gives an extra 15bhp, but I can't really see it....

Port matching the manifolds is a worthwhile mod, but polishing, boring out, etc is a waste of time - The roughness inside the inlet manifold is good for fuel/air atomisation, and no need to enlarge the runners/headers as the carb venturi will still be the pre-engine restricition.

Likewise for the exhaust manifold, in that you want to retain the same diameter/bore all the way through to maintain gas speed/heat/pressure (cue Boyle's Law) to aid turbo spool.

As for the 15hp gain... :coffee:

Oh well..... it's shiney which is always a plus. :D

I've always wanted to get the KTR exhaust mani, but it's insanely expensive!

i think theres been quite a bit of discussion on the tubular manifold option.
i believe its not really of huge benefit plus you loose the tractor sound!:p

All joking aside, losing the tractor sound would actually stop me from getting it.

theres nothing like the good old tractor, the gtt is always so distinctive, theres a local 5 that comes past my house sometimes and i always know its him when im tucked up in bed

http://www.youtube.com/watch?v=WhzeBeqlNJc

You can't beat the signature sound of a 5. :smokin:

Quote:

---

Originally Posted by 5alldaway

http://www.youtube.com/watch?v=WhzeBeqlNJc

---

ooh, tuning on the workshop dyno:cool:

Quote:

---

Originally Posted by Big Supes

You can't beat the signature sound of a 5. :smokin:

---

Ohhhhhh...... really :rolleyes: I beg to differ :coffee:

Hi dudes, slowly getting the bits together for the engine build. :)

I've got a GT28r, K-Tec FMIC and a uprated fuel pump.... just need to decide what to do with the internals...

So, for around 250bhp, do you think the standard bottom-end internals would be ok?? I don't really want to be rebuilding the engine again in 6 months. :wasntme:

At anything close to that level of power you'll be rebuilding pretty often, take my word for it :(

Quote:

---

Originally Posted by Big Supes

I don't really want to be rebuilding the engine again in 6 months. :wasntme:

---

it'll be fine in 6 months, as long as the rebuild after 4 has gone OK...

Quote:

---

Originally Posted by Big Supes

Hi dudes, slowly getting the bits together for the engine build. :)

I've got a GT28r, K-Tec FMIC and a uprated fuel pump.... just need to decide what to do with the internals...

So, for around 250bhp, do you think the standard bottom-end internals would be ok?? I don't really want to be rebuilding the engine again in 6 months. :wasntme:

---

would be making sure your oil pump is up to it too.....

big cam, turbo and 20psi seems to be a winning formula and done quite often.
plus it is suprising how fast that feels.

not to be sniffed at.

im guessing 250 horses from a R5 would be difficult to sustain and even put the power down on the road! let alone how long the gearbox would last.

probably be easier to do with an efi conversion than the carb

Ok, thanks for the input guys. :agree:

Do you think forged pistons and steel liners could be the way to go? Also, what sort of power do you guys think the GT28r @ 20psi will push out with this spec:

KTR Level 3 gas flowed head.
285 Cam
Lightened Flywheel.
KTR FMIC
KTR Group A carb
Induction Kit/stainless exhaust

??

One last question... :o ... what is the max power you guys would recommend to sustain a nice and reliable engine?

Thanks :agree:

what size 28r ?

It's this one: https://www.rtoc.org/boards/showthread.php?t=7318

:)

It's actually a GT2560R, I called it that to simplify it. It's got the 60trim comp wheel and .64 back end

Ahh, thanks Adam.

Isn't is a good job I know so well what I buy. :scratch::laugh:

I was just happy that it would get the job done. :)

BTW, Adam... do you post on the SXOC??

Ummm, no:scared::D

You should, mate. They're a good bunch and there's a ton of info to hand..... all for nada.

:)

You missed the reason for the smileys;)

I do, but I read more than post. I'm not exactly new to the SR20's anyway, so it's only bits and bobs I need to pick up on.

Ooppss.... lol. :D I've found that smilies kinda have different meanings on different forums. I thought you were apprehensive for some reason or another. :confused: My bad. :D

I spent many hours on there after buying an S13. :(

There is alot of info, but like most forums, you need to sift through the crap. I've found everything I need to though, i'll see how things go with the A.

Yeah, I don't know a great deal about the SR, apart from the main differences between it and a CA.

Stage 3a seems like a good option.

Regarding the tubby you sold me, would you have any idea as to what sort of boost/power I should run on standard internals, and what sort of power would that make, approx?

I was a little suprised that most of them seem to run mail order ecu's, although there's options for self mapping. It's still a fortune from tuners. I've got another lump, so i'm sure I can build that for about £3k less than a tuner build.

Power wise, I don't know. I ran it at 20psi and it was a bit violent. Cam choice will make a big difference, and that elbow you've got with it will help it spool up too.

If I were you, i'd be looking at other places for a cam, apart from K-tec:)

just buy my engine! my cam will go very well with your turbo :)

piper 285 and a standard vent carb. that group A will b a pig to fuel and will probably empty in 4th and 5th gear. please feel free anyone to correct that statement.

stick a standard vent carb on it and have one of the pros drill your carb jets properly for you. Dont be wasting time buying over sized main jets.

scoff set my carb up and it runs 20psi with a T28, FMIC and a piper 285 all on the standard main jet.

pop round fella and take the car out for a test drive. 20psi on the road with that spec is enough and i havent yet had to do a rebuild. i will even drop my LM-1 in so you can see the AFR just to proove it fuels ace with a standard main.
i had one headgasket done but that was due to a water hose bursting and i couldnt stop at the time due to roadworks and traffic...warped the head!
that was nothing to do with performance mods or fueling.

if you want more power then maybe have a second carb set up for 25psi and use that for the strip. as i doubt it would be reliable for daily/weekly road use.
then wen it comes to play time o nthe strip...plug n play the carb and have a bleed valve setup to swap between 20 and 25psi.

:smokin:

Quote:

---

Originally Posted by Adam L

I was a little suprised that most of them seem to run mail order ecu's, although there's options for self mapping. It's still a fortune from tuners. I've got another lump, so i'm sure I can build that for about £3k less than a tuner build.

---

Yeah, I think it's all down to price. A tried and tested Jez map seems to be a simple and cheaper way to go for someone who just wants to up the power to a desired level with relative ease.

Quote:

---

Power wise, I don't know. I ran it at 20psi and it was a bit violent. Cam choice will make a big difference, and that elbow you've got with it will help it spool up too.

If I were you, i'd be looking at other places for a cam, apart from K-tec:)

---

Ok, cool. Yeah, I can imagine 20psi from that tubby will be slightly different from what my old T2 delivered. :D

Any recommendations on sourcing the cam?

Quote:

---

Originally Posted by Nayls

just buy my engine! my cam will go very well with your turbo :)

---

Thanks for the offer, but I'm looking forward to getting mine stripped and rebuilt. :)

Quote:

---

Originally Posted by Maka

piper 285 and a standard vent carb. that group A will b a pig to fuel and will probably empty in 4th and 5th gear. please feel free anyone to correct that statement.

stick a standard vent carb on it and have one of the pros drill your carb jets properly for you. Dont be wasting time buying over sized main jets.

scoff set my carb up and it runs 20psi with a T28, FMIC and a piper 285 all on the standard main jet.

pop round fella and take the car out for a test drive. 20psi on the road with that spec is enough and i havent yet had to do a rebuild. i will even drop my LM-1 in so you can see the AFR just to proove it fuels ace with a standard main.
i had one headgasket done but that was due to a water hose bursting and i couldnt stop at the time due to roadworks and traffic...warped the head!
that was nothing to do with performance mods or fueling.

if you want more power then maybe have a second carb set up for 25psi and use that for the strip. as i doubt it would be reliable for daily/weekly road use.
then wen it comes to play time o nthe strip...plug n play the carb and have a bleed valve setup to swap between 20 and 25psi.

:smokin:

---

Only if you were closer, Maka. :(

Yeah, I'm slowly gathering that the group A carbs don't really cut the mustard, I'll definitely take your advise with going back to the standard and getting it drilled.

Looks like it's time to get the bigger cam.... although, I'm starting to think I need to double check my reciept from K-Tec as may already have the 285 cam on there. :confused::D

i had a group A carb with a 28mm vent long time ago.
with a 150 main jet and a 0.9 air corrector at 16psi it ran lean 16:1 afrs

i was pursuaded to use a standard carb, a the time i was i nthe mind set that becuase it was an uprated group A id loose power if i took it off etc.
what a load of **** thinking like that was.

standard carb set up right = trouble free boosting, for fueling anyway.
becareful your wheels dont fly off (coops muwhaha) or bodykit parts dont fly into nearby hedges.
i lost my spoiler at 20psi on a country road, boot lid opened, doors opened, lost a wing mirror glass, blew the ir filter off with compressor surge.
tie wraps solved all the problems (just kidding)

cars solid nowadays

LOL I've bought some new sideskirt clips as it's they're a bit suspect. :D

The group A carb seems to be ok at 20psi with my T2. On boost it pulls pretty hard with no pinking. I'll still be taking your advice though and going back to the standard carb. :agree:

Ok, so it looks like I'll be going with steel liners, standard pistons, gas flowed head, 285 cam, a magic standard carb, and a K-Tec FMIC. :)

Any ideas what sort of boost I will be able to run?

The reason I ask is because, if it's no more than 20 psi, my K-tec double core jobby worked just fine at 20 psi.

Quote:

---

Originally Posted by Big Supes

Ok, so it looks like I'll be going with steel liners, standard pistons.

---

In other words, the opposite of what was reccomended :D

Darn.... :confused:

I was of the understanding that the standard pistons and rods will do fine.... maybe even the liners, but if anything goes up the pod, it's usually the liners.

What's your recommendation, Scoff?

Quote:

---

Originally Posted by Scoff

In other words, the opposite of what was reccomended :D

---

steel pistons :cool:

Ah, you have to think of it from a different angle! Liners fail at santa pod because the engine wasn't tuned properly, or something failed that ment the tune turned bad. They didn't break because they were not strong enough to handle the power. Make them stronger and you no longer have a safety net, or fuse in the system. If you were to put steel liners into the same engine and run with the same crap tune then the pistons would probably melt instead, they're next in line for attack from detonation.

Keep the tune right and a) you'll make more power and b) you won't need fancy liners.

What mart was getting at on page 1 is that all being well (the tune) the pistons are the first weakest link. Ring lands break free or in my case gudgeon pins failed. They're still pretty tough buggers though, they will deal with a little over 200hp pretty well.

EDIT: hadn't seen last post.

Quote:

---

Originally Posted by Scoff

Ah, you have to think of it from a different angle! Liners fail at santa pod because the engine wasn't tuned properly, or something failed that ment the tune turned bad. They didn't break because they were not strong enough to handle the power. Make them stronger and you no longer have a safety net, or fuse in the system. If you were to put steel liners into the same engine and run with the same crap tune then the pistons would probably melt instead, they're next in line for attack from detonation.

---

Gotcha. Leaning out would more than likely cause melt down/liners failing. :agree::agree:

Quote:

---

Keep the tune right and a) you'll make more power and b) you won't need fancy liners.

What mart was getting at on page 1 is that all being well (the tune) the pistons are the first weakest link. Ring lands break free or in my case gudgeon pins failed. They're still pretty tough buggers though, they will deal with a little over 200hp pretty well.

---

Sweet. What's your thoughts on running around 215/230bhp (with the right tune)?

I'd say you could keep standard pistons and liners, just pay good attention to the tuning.

Oki doki. :)

Rob@backyardracing mentioned getting the piston crowns machined in relation to my head hight measures (if its been skimmed alot before).... do you know anyone 'in the know' who could do this as per power expectations?

Quote:

---

Originally Posted by Big Supes

New poster! (less than 10 posts)

Hi guys, looking to order up the parts for my new engine build, but wanted to rack the brains of the guru's before I do.

Here's my current set up:

KTR - Level 3 gas flowed head.
Uprated head gasket set and bolts.
KTR uprated cam.
Group N Clutch.
Lightened Flywheel.
KTR alloy intercooler, group A carb, group A dump valve, induction kit, in-car boost kit.
Hi output starter motor.
Samco hoses
Garrett T2 Turbo
Scorpion Exhaust

The car was running 20psi all the time and never gave me any issues. The main reason for the rebuild is to refresh the bottom-end.... and here's my question........

Would it be ok to fit forged pistons, but not the forged con-rods and steel liners to run 25+ psi?? I know this sounds a bit 'bodge', but there's a massive price difference and TBH, I only want to run a bit more power than what it was before.

Any help would be appreciated.

---

What on earth is a group A dump valve?, makes me laugh all theis level 20 head and level 35 engine complete BS if you ask me why not say the head hjad had this or that done, these tuners put a massive smile on my face with there quotes, change a single bolt must be level 1 then PMSL.

It's just what's on the receipt buddy. :confused::D

Quote:

---

Originally Posted by Big Supes

It's just what's on the receipt buddy. :confused::D

---

Must be a stronger spring lol

Maybe their stores are categorised into sections: N and A.

"Where'd you get that Dump Valve from nipper?"......

"Aisle 'A', boss".

:laugh:

Does anyone have any thoughts on BB pistons and liners??

Considering buying this engine for the bottem-end and then selling for the top half: http://rtoc.co.uk/boards/showthread.php?t=9708

Quote:

---

Originally Posted by Big Supes

Hi dudes, slowly getting the bits together for the engine build. :)

I've got a GT28r, K-Tec FMIC and a uprated fuel pump.... just need to decide what to do with the internals...

So, for around 250bhp, do you think the standard bottom-end internals would be ok?? I don't really want to be rebuilding the engine again in 6 months. :wasntme:

---

I think you need to forget all these fancy parts for the bottom end and build some thing with o.e parts with a few tweeks here and there. As mentioned already a five with 20psi mainfold from a t28 will be quick enough for most. I run 21psi fannymold all with o.e bottom end drove to pod did runs in it all day in the low thirteens on road tyres and then drove all the way home without any problems. Spend the money on some decent wide band kit:)

Quote:

---

Originally Posted by Big Supes

Does anyone have any thoughts on BB pistons and liners??

---

they're standard, what thoughts do you have about them?

Quote:

---

Originally Posted by Andrew Cooke

steel pistons :cool:

---

ooooooo :scared: come on give him a day at least before the steel talk ;) only kiding :D

Quote:

---

Originally Posted by Rob@Backyardracing

ooooooo :scared: come on give him a day at least before the steel talk ;) only kiding :D

---

nobody mention pistons, I mentioned them once but I think I got away with it:laugh:

Quote:

---

Originally Posted by Andrew Cooke

they're standard, what thoughts do you have about them?

---

My only thought is that they might aswell have been called Group A pistons. ;)

Quote:

---

Originally Posted by rs250nut

I think you need to forget all these fancy parts for the bottom end and build some thing with o.e parts with a few tweeks here and there. As mentioned already a five with 20psi mainfold from a t28 will be quick enough for most. I run 21psi fannymold all with o.e bottom end drove to pod did runs in it all day in the low thirteens on road tyres and then drove all the way home without any problems. Spend the money on some decent wide band kit:)

---

Trust me, mate... I would love to forget all these fancy parts and just go with the standard internals. I just don't want to be limited to what other people think is the ideal power limit.

Fit some well known brand forged piston into new standard liners and build yourself a good but otherwise standard bottom end. That will do fine for whatever you want to do.

It isn't so much that you'll be held back by what the internals can handle but rarther you'll find it very hard to make much more than 230hp (not a criticism by the way, just that everybody does). It takes a lot of trial and error to find ways of making much more than that.

Thanks, Scoff.

I may look at standard pistons, liners, but forged ringlands, then aim for around 230 max bhp......

Do you think the bottom-end of this engine would be up to what I want?

http://rtoc.co.uk/boards/showthread.php?t=9708

id like to try a bigger turbo on mine at some stage , to really test the internals , im actually feeling now i shouldve went for a bigger turbo to start with ,i seem to be on the limits of this t25 running 28psi and making 230@wheels ,is this good power for the turbo size? compaired to say others running t25's

Are you running standard internals?

EDIT: Just looked at your profile. :agree:

Ring lands are part of the piston. Yes bottom end looks fine to me.

Ahh... so it's the area between the rings?

Ok, I may go with that engine and save myself some time with mine.

Thanks for the help and advice. :agree:

Wossner forged pistons or the one's K-tec use?

:)

Quote:

---

Originally Posted by Big Supes

Wossner forged pistons or the one's K-tec use?

:)

---

Niether:)

Who'd you recommend matey?

:)

Oh well, think I'll go with K-Tec forgies...

K-Tec haven't let me down yet.

Quote:

---

Originally Posted by Big Supes

Wossner forged pistons or the one's K-tec use?

:)

---

what's the difference?

[quote=Scoff;94925]Fit some well known brand forged piston into new standard liners and build yourself a good but otherwise standard bottom end. That will do fine for whatever you want to do.[quote]

Thats what i would do if i was going to change anything on the bottom end!

Price.... K-tec sell theirs for an extra £46.

I also was looking for some feedback as to which ones people seem to favour.

Quote:

---

Originally Posted by Andrew Cooke

what's the difference?

---

They may be wossner or those PEC own-brand ones. Not that there is anything wrong with either, but I'd be a little more comfortable with a better known brand.

Quote:

---

Originally Posted by Big Supes

Price.... K-tec sell theirs for an extra £46.

I also was looking for some feedback as to which ones people seem to favour.

---

so why pay an extra £46 for the same thing?

Quote:

---

Originally Posted by Andrew Cooke

so why pay an extra £46 for the same thing?

---

Oh sorry, I hadn't realised they were.

:confused:

Quote:

---

Originally Posted by Scoff

They may be wossner or those PEC own-brand ones. Not that there is anything wrong with either, but I'd be a little more comfortable with a better known brand.

---

Scoff, which brand would you go for mate?

Quote:

---

Originally Posted by Big Supes

Oh sorry, I hadn't realised they were.

:confused:

---

you just said that they were

Ive got some pistons and liners for sale...:D...:scared:...:D

Quote:

---

Originally Posted by Andrew Cooke

you just said that they were

---

Did I fcuk. I wanted to know which ones people favoured here, but that seems to be a problem for you.

Quote:

---

Originally Posted by Spooky

Ive got some pistons and liners for sale...:D...:scared:...:D

---

SHameless. :D

Buy them....180 quid delivered...you dont need to go forged this forged that :D

Na... I'm gona have to go "thanks but no thanks" instead. :cooter:

They'd be no point me speaking to the guys in the know if I did.

Quote:

---

Originally Posted by Big Supes

They'd be no point me speaking to the guys in the know if I did.

---

People will still give advice if you do fit standard pistons mate, to be honest i can't see the point of fitting expensive forged items when the originals will do. Unless your going to be pushing the engine hard then i'd prob invest in them.

Quote:

---

Originally Posted by Markey Mark (BD)

People will still give advice if you do fit standard pistons mate, to be honest i can't see the point of fitting expensive forged items when the originals will do. Unless your going to be pushing the engine hard then i'd prob invest in them.

---

I'm going to aim for 250 bhp despite how hard it will be to apply it. :D

Quote:

---

Originally Posted by Big Supes

I'm going to aim for 250 bhp despite how hard it will be to apply it. :D

---

If you want to go for it mate then yes go for some forge ones, one thing i will say is if you are aiming for high bhp i'd sell that KTR cam you have and invest in a better or custom ground cam as that cam will not get you anywhere near that sort of power.

To get to that sort of power it won't be reached with off the shelf bits

I don't know really, I just think that when it comes to important stuff like that you aught to put something you trust in there. JE, accralite, arias will all sell you something that will work perfectly. I've seen a few too many wierd issues with wossner to be 100% comfortable with them, but that may be because so many more people buy and fit them compared to other brands. And then there is the PEC imports of un-known origin. I have a phobia of buying stuff from people who refuse to tell you the brand. PEC are a bag of tossers to deal with diretly, the most unhelpfull set of clowns I know, I wouldn't buy anything from them on principal, let alone because of my concerns about their products.

Quote:

---

Originally Posted by Markey Mark (BD)

If you want to go for it mate then yes go for some forge ones, one thing i will say is if you are aiming for high bhp i'd sell that KTR cam you have and invest in a better or custom ground cam as that cam will not get you anywhere near that sort of power.

To get to that sort of power it won't be reached with off the shelf bits

---

Appreciated mate. :agree:

There's definitely going to be some obstacles in the way, but I'd just like to have the foundations there to slowly build upon.

Who knows, the efi route may be the way to go eventually.

Quote:

---

Originally Posted by Scoff

I don't know really, I just think that when it comes to important stuff like that you aught to put something you trust in there. JE, accralite, arias will all sell you something that will work perfectly. I've seen a few too many wierd issues with wossner to be 100% comfortable with them, but that may be because so many more people buy and fit them compared to other brands. And then there is the PEC imports of un-known origin. I have a phobia of buying stuff from people who refuse to tell you the brand. PEC are a bag of tossers to deal with diretly, the most unhelpfull set of clowns I know, I wouldn't buy anything from them on principal, let alone because of my concerns about their products.

---

Ok, cool... I'll check out JE, accralite and arias. :agree:

Regarding PEC, are these the guys you suspect K-Tec source theirs from?

this is what happens to wossner forged pistons and pec conrods

yyeeouuch.... did they lean out?

What set up and boost were you running by the way?

Engine is coming out this Saturday.... looking forward to getting the old girl going again!!

just ran the engine in and it gave way at 22 psi the carb is set up to run 30psi

Quote:

---

Originally Posted by Big Supes

I also was looking for some feedback as to which ones people seem to favour.

---

J.E's, as I posted on page one of this thread...

Sh!t, that's not good. Sorry to hear that mate. :(

I'm definitely going to be running a AFR gauge when it comes to turning up the boost. That and wearing home made stethoscope running back into the car from the engine for the first high power run. :D

Quote:

---

Originally Posted by Mart

J.E's, as I posted on page one of this thread...

---

Sweet. :agree:

I emailed JE, Accralite and Arias.

If you're gonna fit those pistons to o.e rods, you'll have to get the rods machined to accept the floating pin.

Shouldn't cost you that much, but it is another outlay/aggro of finding a local company who can do such work.

Ok, thanks for the heads up.

I've got a friend who may be able to help with that.

Can anyone help with these questions: Please advise bore diameter and whether fully floating or press -fit pin?

I intend to use the original con rod if that makes a difference.

Quote:

---

Originally Posted by turbo ted

this is what happens to wossner forged pistons and pec conrods

---

Ted, do you know what skirt clearance you were running? Had smiliar on something else, was a rebuild on old pistons as a favor, mic'ed up ok, but pulled up the bores. Issue was the skirt deflects, but not around the / by the boss support for the pin. They then pick up on the edges of the piston and not the main centre section of the skirt, looks like similiar if I'm reading your pics right. Just need to slightly increased clearance. Cossie boys have the same issue, and generally go at 0.07 - 0.08mm.

Quote:

---

Originally Posted by Big Supes

Did I fcuk. I wanted to know which ones people favoured here, but that seems to be a problem for you.

---

lol you did

never measured the skirt clearance because i ran these pistons for over 12months on standard conrods at 25psi + of boost,now fitted pec forged floating conrods which have caused this problem now i got to hone the liners out to make more clearance:cry:

Quote:

---

Originally Posted by Dan y

lol you did

---

PM'd

rob, it could have been that the piston was distorted when the old pin was pressed out - since you mentioned the piston didn't seem to rock on the gudgeon pin properly before fitting.

Quote:

---

Originally Posted by turbo ted

never measured the skirt clearance because i ran these pistons for over 12months on standard conrods at 25psi + of boost,now fitted pec forged floating conrods which have caused this problem now i got to hone the liners out to make more clearance:cry:

---

Just out of curiosity, what made you go for the forged conrods after the running the standard ones?

i have all the tecnical data at home regarding wossners sizes of rods, i went for the woosner rods just out of simplicity due to the gudgeon pin slipping out due to the rod being over heated but lost my trust in them and went for c clip style.

Quote:

---

Originally Posted by Big Supes

Just out of curiosity, what made you go for the forged conrods after the running the standard ones?

---

just wanted to make the engine stronger so i can try and get more power out of it:crap:

Bollocks. :(

Ok, I was just checking that's all... just incase you had problems running o.e conrods or something.

Quote:

---

Originally Posted by Mart

J.E's, as I posted on page one of this thread...

---

Sorry Mart, only just spotted this since coming back to this thread.

Just emailed J.E.... just hoping there's a quick turn around for delivery. All other engine bits are now on order, apart from a custom cam.

Any recommendations on what cam to go for (aiming for around 250bhp)?

Man, I am Skint Eastwood!!!

Match the cam to the turbo.

J.E's are v good - You won't have a problem with them.

I've used JE pistons for my last rebuild.Till now they are ok.

Quote:

---

Originally Posted by Big Supes

Wossner forged pistons or the one's K-tec use?

:)

---

I think they are the same.They are wossners an I think they are the cheap ones judging by the size of the conrods.

Quote:

---

Originally Posted by Mart

Match the cam to the turbo.

J.E's are v good - You won't have a problem with them.

---

What sort of money are we talking for a custom grind cam from the likes of catcams?

Not sure about CatCams, but Kent Cams charged me ~£120 back in the day.

I think Piper was a similar price too - Sparkie should be able to confirm that, as he sent a few sticks Piper's way to be re-ground over the years.

Re: Power - What route to go now??

Take a step back, Have a good read, Then what it will explain if you read all infomation correct is that if you dont listen to, sound good advise given in this topic
and try and stay well within your limits.
Your going to end up with a broke car sat there pissing you right off.

Its not just about bolting this and that on, there is a fine balance when it comes to silly power 200bhp + on these little turbo engines, 1 mistake major fail ;)

if you have enough coin have a play and learn the hard way......

if not i'd ask the question you just asked and got plenty of good ideas,

remember the more money you spend on said engine, if and when it fails running high power , its going to cost you more, so keep it cheap but and listen to what people say.

You can have standard engine, decent cam, nice lungs "turbo" good air/oil/water cooling and have a reliable 200hp without it costing a packet.

like you said further up in topic joining RTOC is well worth the £25 squid and will save you a lot, like it has for me. no point getting carried away thinking you can out do people who have got borad trying to get more power out of said engine :scared:

stuart clark has the fastest and your not going to out do his car ;)
its for sale i think why dont you just buy that :D

https://www.rtoc.org/boards/member.php?u=336
https://www.rtoc.org/boards/showthread.php?t=10495

Quote:

---

Originally Posted by Mart

Match the cam to the turbo.

J.E's are v good - You won't have a problem with them.

---

Ok, cool. I've heard "Catcams" being thrown around these parts so I take it they're a recommended supplier. I may give them a call.

Cheers Mart

:agree:

Quote:

---

Originally Posted by dave j gtt

Re: Power - What route to go now??

Take a step back, Have a good read, Then what it will explain if you read all infomation correct is that if you dont listen to, sound good advise given in this topic
and try and stay well within your limits.
Your going to end up with a broke car sat there pissing you right off.

---

Sure, I wouldn't be posting on this thread if I felt otherwise.

Quote:

---

Its not just about bolting this and that on, there is a fine balance when it comes to silly power 200bhp + on these little turbo engines, 1 mistake major fail ;)

---

Noted.

Quote:

---

if you have enough coin have a play and learn the hard way......

if not i'd ask the question you just asked and got plenty of good ideas,

remember the more money you spend on said engine, if and when it fails running high power , its going to cost you more, so keep it cheap but and listen to what people say.

You can have standard engine, decent cam, nice lungs "turbo" good air/oil/water cooling and have a reliable 200hp without it costing a packet.

like you said further up in topic joining RTOC is well worth the £25 squid and will save you a lot, like it has for me. no point getting carried away thinking you can out do people who have got borad trying to get more power out of said engine :scared:

stuart clark has the fastest and your not going to out do his car ;)
its for sale i think why dont you just buy that :D

https://www.rtoc.org/boards/member.php?u=336
https://www.rtoc.org/boards/showthread.php?t=10495

---

Yeah, thanks all the same, but it's time to move on and up the power. I'm not looking to "out doing people" on here. Why would I? I don't even know anyone on here and to be honest, there's always someone out there faster, minter, better, anyway.... and fair play to them. I don't quite know how you've come to this assumption.... :confused:

Can I not just find the tolerances and options of tuning my engine without people telling me what I should do?

Quote:

---

Originally Posted by Mart

Not sure about CatCams, but Kent Cams charged me ~£120 back in the day.

I think Piper was a similar price too - Sparkie should be able to confirm that, as he sent a few sticks Piper's way to be re-ground over the years.

---

Piper do charge around £120 last time i had one sent away..

Yeah, thanks all the same, but it's time to move on and up the power. I'm not looking to "out doing people" on here. Why would I?

- Like has been said a new turbo will make you feel alot more power that on stock t2 or what ever you have.
- Why would you ?: every human wants more/better or most do.

I don't even know anyone on here and to be honest, there's always someone out there faster, minter, better, anyway.... and fair play to them. I don't quite know how you've come to this assumption.... :confused:

- Theres no fast gtt engine than the one in links that i posted ;)

- your asking how far to go b4 its a joke and re -build after rebuild is needed :confused:
people say and you still want 250hp when peeps have said it become hard after 230hp not to lose bolts

Can I not just find the tolerances and options of tuning my engine without people telling me what I should do?[/quote]

your asking people to tell you what to do ! rather than a like a few of the tech posters in this topic have done. spend years/ time /money /sweat and shed tears. in finding what is the best, most affective way to tune with out wastin money ;)

dont take me the wrong way am just trying to help you find what route to go now.
ai

i was a newbie when it disapeared, RIP old rtoc site :cry:

Quote:

---

Originally Posted by dave j gtt

- Why would you ?: every human wants more/better or most do.

---

I disagree. There's a lot of people out there who also wouldn't give a flying fook what people (who they don't know) are doing with their cars.

Quote:

---

- Theres no fast gtt engine than the one in links that i posted ;)

---

No offence, but I didn't check the link until now. You can guess why, right?

Quote:

---

- your asking how far to go b4 its a joke and re -build after rebuild is needed :confused:
people say and you still want 250hp when peeps have said it become hard after 230hp not to lose bolts

---

From what I've gathered, the main focus is the tune with the C1J. This going to be my main priority once the engine is together.... now, while I choose the internals and the bolt on bits, don't you think it's a good idea to aim high?.... as, when it's actually running, it'll be gradually tuned and carefully taken up to a safe limit. Where this is limit is I have no idea at this stage, but at least there won't become a point where I'm regretting not choosing the bit's needed for that tune.

Quote:

---

your asking people to tell you what to do !

---

No I'm not. I'm asking for 'advice'.

Quote:

---

rather than a like a few of the tech posters in this topic have done. spend years/ time /money /sweat and shed tears. in finding what is the best, most affective way to tune with out wastin money ;)

---

Are you suggesting that I have wasted money?

Quote:

---

dont take me the wrong way am just trying to help you find what route to go now.
ai

---

Yeah sure, if you've got any more constuctive posts, fire away. :laugh:

It's (nearly) always interesting to read these types threads so I'm not knocking it, but I think the advice from most people would be similar to the first reply posted (which was in May!). It went something like this:

Standard piston and liners
Standard carb (not a group A)
Decent intecooler
T25 or T28 turbo
AFR gauge of some sort
Cam (Piper 285 or CatCams 5500327 with appropriate valve springs)
1.5bar MAP


Before you go searching for 250+bhp (and all of the associated expense and driveability problems this will bring) try the above.


Invest all your research time in learning how to tune the carb and detect knock; if you do this well then you'll have a very quick car that won't let you down (much).

Quote:

---

Originally Posted by David H

1.5bar MAP

---

Thats about standard boost then :cooter:

I'm sure the original postee ment to say manifold pressure :)

Quote:

---

Originally Posted by Scoff

Thats about standard boost then :cooter:

I'm sure the original postee ment to say manifold pressure :)

---

No, I made that mistake all by myself :-)

I still say 250hp out of a c1j is gonna bring a whole world of pain & unreliabilty. Anywhere bar a drag strip & that much power isn't gonna be useable to its full potential anyway, but each to their own & good luck with the build :agree:

Have to agree with Mart on this one, having had a car pushing around 220bhp as a road/drag car it takes a fair bit of doing keeping an eye on everything, I had an AFR gauge, EGT gauge, oil pressure gauge, boost gauge... you get the idea & then there's the hours of tuning the fecking carb to run the boost, had it fueling for 24psi manifold but it still started to lean out @ 6k.... It's all ok but it starts to become your life .lol. My wife, my poor, poor wife.. :ashamed:

Still I'd do it all again though :p

Quote:

---

Originally Posted by 5teve L

Still I'd do it all again though :p

---

Just get a honda tho instead ste :D

I know this may upset the hardcore gtt fans but if you want that much power why not bin the c1j and do what others have done and fit something bigger with a better flowing head, no 25mm restrictor and no weak valve train. Even the trusty valver motor at pony boost will make what power you want with a lot more reliability.

Quote:

---

Originally Posted by David H

It's (nearly) always interesting to read these types threads so I'm not knocking it, but I think the advice from most people would be similar to the first reply posted (which was in May!). It went something like this:

Standard piston and liners
Standard carb (not a group A)
Decent intecooler
T25 or T28 turbo
AFR gauge of some sort
Cam (Piper 285 or CatCams 5500327 with appropriate valve springs)
1.5bar MAP


Before you go searching for 250+bhp (and all of the associated expense and driveability problems this will bring) try the above.


Invest all your research time in learning how to tune the carb and detect knock; if you do this well then you'll have a very quick car that won't let you down (much).

---

:agree: david and my next task is to try and learn to art of: how to tune the carb and detect knock :scared: :wasntme: i'll be right....

:agree: also with mart's above post:coffee:

Quote:

---

Originally Posted by Rob@Backyardracing

Just get a honda tho instead ste :D

---

Yeah Rob, for sure, something else with liners to crack :laugh:, these T16 engines in the Rover are pony for getting power out of on the cheap.... :sad:

Quote:

---

Originally Posted by Mart

I still say 250hp out of a c1j is gonna bring a whole world of pain & unreliabilty. Anywhere bar a drag strip & that much power isn't gonna be useable to its full potential anyway, but each to their own & good luck with the build :agree:

---

I'm just setting down the foundations for big power at the moment.... if the tune is good, who knows where I'll get, but I either way, I don't intend to push beyond the limit.

Any volunteers for drilling my jets once it's running? I'll make sure your time is worth while.

:)

Quote:

---

Originally Posted by Big Supes

I'm just setting down the foundations for big power at the moment.... if the tune is good, who knows where I'll get, but I either way, I don't intend to push beyond the limit.

Any volunteers for drilling my jets once it's running? I'll make sure your time is worth while.

:)

---

go for 200bhp an just give it death !!

anymore an you will hit some niggly issues..like POP !!!

more would be ok i think if you doing the 1/4 mile but for
general use an abuse it will not last to long with out problems.

:)

Quote:

---

Originally Posted by 5teve L

Yeah Rob, for sure, something else with liners to crack :laugh:, these T16 engines in the Rover are pony for getting power out of on the cheap.... :sad:

---

There stronger than most peeps think the stock honda sleeves, a good few peeps making big HP with stock sleeves... We had to break ours simiply to find our limits :)

Quote:

---

Originally Posted by Big Supes

I'm just setting down the foundations for big power at the moment.... if the tune is good, who knows where I'll get, but I either way, I don't intend to push beyond the limit.

Any volunteers for drilling my jets once it's running? I'll make sure your time is worth while.

:)

---

I dont mind lending a hand providing you have wide band, if I were you I would take the carb body to a local engineering firm and have the second stage bush machined out to accept an a.c jet.

Quote:

---

Originally Posted by rs250nut

I dont mind lending a hand providing you have wide band, if I were you I would take the carb body to a local engineering firm and have the second stage bush machined out to accept an a.c jet.

---

Thanks mate, appreciated. :) A wide band will be definitely be fitted when the tuning starts. :agree:

I'm going to keep an eye out for a second hand standard carb. When I get one, could you recommend me someone to do that?

Quote:

---

Originally Posted by J$£5GTT

go for 200bhp an just give it death !!

---

It couldn't have been much less (if at all) on the previous set up. Not that I am complaining. :D

Quote:

---

anymore an you will hit some niggly issues..like POP !!!

more would be ok i think if you doing the 1/4 mile but for
general use an abuse it will not last to long with out problems.

:)

---

Yeah, I'm certainly going to take extra care with taking the power up.... regarding general use and abuse... I tend to drive like an old man 80% of the time and the other 20% is just general grins and p!sssing off the big guns who pull up next to me in their Type R's/BMW's. It's especially pleasing when they have their girlfriends in the car. :D

Just got off the phone to a J.E piston supplier and they want to know what spec I would need the forged pistons (as they're apparently custom)? He also mentioned that the standard compression (7.9 to 1) was too low? :confused:

I'm sending them one of my old pistons as a sample, but to be clear, all I want is standard compression, bore size and valve seats?

Cheers

7.9:1 is standard.......

Quote:

---

Originally Posted by Big Supes

Just got off the phone to a J.E piston supplier and they want to know what spec I would need the forged pistons (as they're apparently custom)? He also mentioned that the standard compression (7.9 to 1) was too low? :confused:

I'm sending them one of my old pistons as a sample, but to be clear, all I want is standard compression, bore size and valve seats?

Cheers

---

Thats standard compression mate, as you say send him a standard piston and ask for it to be copied.

Yep. :)

He mentioned this standard compression was too low and that if these pistons were going in his engine he would up the compression. :confused:

Just wanted to run this through you guys....

Well I personally wouldn't be doing that.

Quote:

---

Originally Posted by Markey Mark (BD)

Thats standard compression mate, as you say send him a standard piston and ask for it to be copied.

---

Cool... will do. Just wasn't sure why he thought the standard compression was too low.

Cheers. :)

Quote:

---

Originally Posted by Alex

Well I personally wouldn't be doing that.

---

Yeah, I thought it was a bit strange. The head gasket is going be under enough strain as it is.

Quote:

---

Originally Posted by Alex

Well I personally wouldn't be doing that.

---

I would! :)

I'd probably go for flat topped pistons decked to the same height as the liners and sort the CR out in the head. But it's your engine and you need to do what you think is best.

Quote:

---

Originally Posted by Big Supes

Yeah, I thought it was a bit strange. The head gasket is going be under enough strain as it is.

---

Not strange at all, my engine that done the 12.3 quarter mile was running 8:1.1, did the time at 20psi but ran it at 24psi for the rest of the day.

But, wouldn't that time be factored by many other variables aswell, such as: suspension, wheels, tires, weather, driver.... ?

You could argue that it would/could have run that time with the standard compression.

Either way, I wasn't really commenting on performance... I was more concerned with reliability (HG failure).

Not saying the raised compression was the only reason for my time, just pointing out that its not nessecially a bad thing running slightly higher compression ratio and doesn't always lead to HG failure.

Point taken. :)

Do you still run that compression ratio now Mark? What made you change in the first place if you don't mind me asking?

No reason why the HG should fail if everything else is in order.

If I was to rebuild another c1j engine again, I'd be going higher c/r for sure.

What reasons would lead you to up'ing the compression ratio Mart?

Quote:

---

Originally Posted by Big Supes

Point taken. :)

Do you still run that compression ratio now Mark? What made you change in the first place if you don't mind me asking?

---

I've now sold that engine on as i have a Volvo lump in my red 5, but have now got a gt lump in a campus and may raise the compression abit on that next year if it comes apart.

It was back in 2005 i had it done, can't rerally remember why i had it done:D Would do it again though.

Quote:

---

Originally Posted by Markey Mark (BD)

I've now sold that engine on as i have a Volvo lump in my red 5, but have now got a gt lump in a campus and may raise the compression abit on that next year if it comes apart.

It was back in 2005 i had it done, can't rerally remember why i had it done:D Would do it again though.

---

I'd be tempted by an engine conversion, but I'm fond of the little C1J.... to the point I'm keeping the original exhaust manifold to keep that signature GTT sound.

I'll have a good read and talk to a few peeps about this... just need to understand all the implications around do it.

:)

Quote:

---

Originally Posted by Big Supes

What reasons would lead you to up'ing the compression ratio Mart?

---

Improved drive-ability, better fuel consumption, torque/hp gain.

I suppose it would help with lag aswell.

Going to look into this.... thanks for the opinions guys.

:agree:

defo raise the comp, got 3 r5gtts here all on higher comp, 1 c1j running carb, another cj1 runnin efi and my f4r turbo and defo say over the std or low comp its alot better drive :D

I'd be tempted by an engine conversion, but I'm fond of the little C1J.... to the point I'm keeping the original exhaust manifold to keep that signature GTT sound.


Mostly everyone on here run the oe ex manifold, theres no major gain on any other design over standard

That's good to know GttNutter. :cool:

I was going to look into sanding out any roughness in the casting/joins instead of replacing it for a tubular mani - improve the flow while keeping the sound. :smokin:

Quote:

---

Originally Posted by steveR5GTT

defo raise the comp, got 3 r5gtts here all on higher comp, 1 c1j running carb, another cj1 runnin efi and my f4r turbo and defo say over the std or low comp its alot better drive :D

---

Nice... what C.R are they running?

:)


Woohoo.... my 400th post. :beer:

As said compression will give you power/torq and higher comp isnt a problem aslong as its managed correctly. Id build your engine to what you intend to use it for, Id also look in to the piston tapper, yet again depending on your tune... :)

Quote:

---

Originally Posted by Rob@Backyardracing

As said compression will give you power/torq and higher comp isnt a problem aslong as its managed correctly.

---

Would this differ from a normal engine? Honest question. :)

Quote:

---

Id build your engine to what you intend to use it for, Id also look in to the piston tapper, yet again depending on your tune... :)

---

TBH Rob, I'm fairly confident in putting the engine together and getting it running, but I'm fairly inexperienced when deciding on compression ratios/dished/flat topped/oval pistons/piston tapper etc....

My intention with the engine is for the odd Santa Pod run/track day, but other than that, I want to have a solid, powerful lump under the bonnet.

Depends what you mean by differ?

Raisng the compression is bascily what a turbo is doing, but by shifting the base raito say from 7.1 - 8.1 via pistons/head or what ever, your closer to the det threshold with the same amount of boost pressure, therefore closer for det to occur. If you can control the fueling/ign your fine as said. Also rasing the compression will increase low/mid range torq too so extra torq at given rpm = extra power aswell.

I spend most of my time building drag engines and torq IMO i dont want alot of (of course to a degree or i wouldnt move :)....other peeps mite disagree) i like to control and limit this to save on breakages but increase the rpm/flow best i can. With my engines id chose a greater tapper and Piston to wall clearance (due to the cyl heat id make) for room for expansion without seizure or bore scoring. A forge will control heat better than cast to bare in mind. But too large and the heat within a piston can not conduct away to the bores so choose wisely.. hence choose a piston to your tune...

Quote:

---

Originally Posted by Mart

No reason why the HG should fail if everything else is in order.

If I was to rebuild another c1j engine again, I'd be going higher c/r for sure.

---

But wouldn't raising the boost (for example) a couple of PSI gain any HP/torque advantage that gave back? Plus you'd be less likely to incur det? :scratch:

PS... It's funny isn't it - a while back a lot of people were going low comp as that was (at least in some eyes) the way to go. Now people are going high comp! :coffee:

Quote:

---

Originally Posted by Alex

But wouldn't raising the boost (for example) a couple of PSI gain any HP/torque advantage that gave back? Plus you'd be less likely to incur det? :scratch:

PS... It's funny isn't it - a while back a lot of people were going low comp as that was (at least in some eyes) the way to go. Now people are going high comp! :coffee:

---

What next alex?

Quote:

---

Originally Posted by Rob@Backyardracing

Depends what you mean by differ?

Raisng the compression is bascily what a turbo is doing, but by shifting the base raito say from 7.1 - 8.1 via pistons/head or what ever, your closer to the det threshold with the same amount of boost pressure, therefore closer for det to occur. If you can control the fueling/ign your fine as said. Also rasing the compression will increase low/mid range torq too so extra torq at given rpm = extra power aswell.

---

This is pretty much what I mean by differ - by being closer to the det threshold with the same amount of boost etc. It's just certain things that'll have to be taken into account when tuning.

Quote:

---

I spend most of my time building drag engines and torq IMO i dont want alot of (of course to a degree or i wouldnt move :)....other peeps mite disagree) i like to control and limit this to save on breakages but increase the rpm/flow best i can. With my engines id chose a greater tapper and Piston to wall clearance (due to the cyl heat id make) for room for expansion without seizure or bore scoring. A forge will control heat better than cast to bare in mind. But too large and the heat within a piston can not conduct away to the bores so choose wisely.. hence choose a piston to your tune...

---

Sorry to be a flid, but what do you mean by a greater tapper? Also, do you think the standard piston to wall clearance would be ok to run 230+ everyday?

Regarding the heat issues.... I'll be running a bigger rad and a separate oil cooler on a thermostat.... all this being said, the car won't be held wide open for long periods in the higher gears (unless it's doing it's rare Santa Pod run).

Quote:

---

Originally Posted by JRP

What next alex?

---

Replacing the engine with a good one one, surely! :laugh:

:laugh:

Quote:

---

Originally Posted by Alex

Replacing the engine with a good one one, surely! :laugh:

---

:laugh:

Quote:

---

Originally Posted by Alex

But wouldn't raising the boost (for example) a couple of PSI gain any HP/torque advantage that gave back? Plus you'd be less likely to incur det? :scratch:

PS... It's funny isn't it - a while back a lot of people were going low comp as that was (at least in some eyes) the way to go. Now people are going high comp! :coffee:

---

Not sure if that last comment was aimed at me, but I've never been a fan of low(er) c/r & have never advised it on here or to anyone running a c1j.

To a degree o.e c/r is fine, but a higher c/r will always give you improved (off-boost) drive-ability, and naturally more power overall. Of course, that's offset by the fact that, as you rightly say, the detonation threshold point is now lower, but that's nothing that can't be sorted by tweaking the ignition and/or adding a bit more 'on-boost' fuel, running water injection, or even better, running a full efi setup.

For drag applications, where boost is king, it's probably not worth running a high c/r, possibly with the exception of having efi in situ, but for track & everyday road-use, I'd recommend a higher c/r everytime.

No, not aimed at you Mart. It's just I remember a lot of people running low comp pistons and also a lot of tuners selling them way back when (showing my age?!).....

I see the advantages in running higher C/R on a day to day basis as you mentioned, It's just my feeling for ultimate power you'd be better off with standard. :agree:

Quote:

---

Originally Posted by Alex

No, not aimed at you Mart. It's just I remember a lot of people running low comp pistons and also a lot of tuners selling them way back when (showing my age?!).....

I see the advantages in running higher C/R on a day to day basis as you mentioned, It's just my feeling for ultimate power you'd be better off with standard. :agree:

---

Thing is tuners sold them as its was the only way to solve det and run more boost, they didnt have much option to tune IGN and the way they tuned carbs was dog ****.

The standard compression of the GT is low, and to low for factory boost levels, but i guess its what renault did to keep the engine safe with that **** carb in place. But remember these days we have ways to tune ign and manage the carb alot better and with EFI etc etc its easier to control det. Ill point out also that the fastest FWD uk car runs around 10.0 -1 with around 40psi of boost...

With my old car runing 120mph trap this was with a lower CR by just shaving the tops to flat tops, i did this due to running NOS and only having the flywheel pick up to adjust timing. At stock CR with say 25psi and 25hp shot you will det (well i did). i had to drop this CR so i could raise the NOS more, which out ways the power lost by dropping compression. I also used my wet kit like a fith injector to help aid the fueling of the carb. If i had EFI i would have done my build differently.

Dudes... just looking to buy my cam... Cat Cams have recommended their 5500327 profile cam, but I'm struggling like mad as to how the hell you can find it on their website and buy it?!?! :confused:

I've got a feeling they haven't updated their website so I'll have to give them a call first thing to purchase.

Quote:

---

Originally Posted by Big Supes

Dudes... just looking to buy my cam... Cat Cams have recommended their 5500327 profile cam, but I'm struggling like mad as to how the hell you can find it on their website and buy it?!?! :confused:

I've got a feeling they haven't updated their website so I'll have to give them a call first thing to purchase.

---

That's the best thing to do anyway as you can haggle on the phone :)

Nayls... I like your style. :D:agree:

Maybe they'll be able to do me a deal if I get the vernier pulley aswell.

Quote:

---

Originally Posted by Big Supes

Nayls... I like your style. :D:agree:

Maybe they'll be able to do me a deal if I get the vernier pulley aswell.

---

i negotiated a deal on cam only, i never pay the advertised price though ;)

WTF? Quality Engineered Products (Cat Cams UK Supplier) phone has been engaged all day?

They've been a pain in the arse with responding to emails... they're website is dog poop... thinking about giving Piper a call tomorrow to see what they suggest.